Yamaha Silent SB Series Service Manual page 27

•TEST MODE
Test mode has two functions that are sensor test and tone generator version check.
The keys that sound unusually or nothing in the STEP 3 need to be checked by this mode.
TEST MODE 1
Hold A,B,C (1,3,4 keys) simultaneously and turn on the power until it clicks, then release keys.
When a key is depressed, the 4 different beeps (approx. K1/2.7 mm, K2/4.5 mm, K3/6.3 mm, K4/8.1 mm)
tell the sensing conditions in 10 mm key depth stroke.
When K1 beeps too early --- Key leveling is too low or Key sensor is too high.
When K4 beeps too late or nothing --- Key leveling is too high or Key sensor is too low.
(Refer to the former page bottom for the acoustic standard.)
The correct sensor height is 4.2 mm (+1 mm / -1 mm) between sensor top and black key bottom
when the black key is fully depressed. (Fig. 7)
Fig. 7
The key sensor has 4 height adjustment screws at base end, 30 key, 58 key and treble end. Then key
sensor measurement on the next page is recommended.
Check STEP 3 finally.
If the pedal sustain functions (right pedal) incorrectly in STEP 3, it can be inspected with 3 steps of
pedal beeps by this test mode. Check the first beep sounds when the pedal goes down 1 mm and the
3rd beep must sound before its stroke end. The adjustment is done by the VR adjuster on the main
board (MN board) with a small flat screw driver. (Fig. 8)
The soft / left pedal has a leaf sensor and it should give the beep when the hammer rail has moved
2-3 mm from it's rest position. The adjustment is done by the screw on the sensor bracket. (Fig. 9)
Fig. 8
V R
4.2mm 4.2mm 4.2mm 4.2mm 4.2mm
Fig. 9
VR adjuster
SILENT SB SERIES
10mm 10mm 10mm 10mm 10mm
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